The present inventions relate to a resin molded body, its receiving jig and a method for manufacturing a push button switch member using the resin molded body and the receiving jig.
In a conventional method, a plurality of resin molded parts has been manufactured by processes comprised of: (i) a process for forming a resin molded body, wherein the resin molded body comprises a plurality of resin molded parts connected at its side faces each other by gates (hereinafter called “side gates”); and (ii) a process for separating the resin molded parts from the side gates of the resin molded body.
For example, Japanese Patent Laid-Open Publication No. H08-183072 discloses a resin molded body having runners, wherein the resin molded parts and the runners are connected by the side gates of the parts. The conventional method has been used for manufacturing a push button switch member of a cellular phone and the like.
Recently, some of cellular phones have front parts with top faces which are illuminated by a light source arranged at the back faces of the front parts. The front parts are manufactured as following processes. First, a resin molded body having transparent resin molded parts for a push button switch member is produced. Then, the top faces and the side faces of the transparent resin molded parts are coated with light shielding paint except for predetermined part of the top faces which are designed to be bright. Finally, the resin molded parts are separated from the resin molded body.
Using the above method for manufacturing the front parts from the resin molded body having the side gates, some region of the side faces of the resin molded parts are not painted with light shielding paint, because the places to where the side gates were connected were not painted with the paint in the coating process. In case of using the front parts as a push button switch member, light leaks through the non-painted regions from back side.
In order to meet the needs of size reduction of a cellular phone, a clearance between keys which are major front parts of the push button switch members, is becoming extremely narrow. In case of using the front parts manufactured from the resin molded body having the side gates, a part of the gates is remained and causes a trouble in key operation. As a solution for the light leakage and for the trouble in key operation, resin molded parts would be manufactured from a resin molded body having gates connected at back face of each resin molded part (hereinafter called “overlap gates”). The back faces of resin molded parts to where the overlap gates would be connected are not needed to be coated by light shielding paint. By using the overlap gates, the light leakage from the non-coating regions of the side faces of the resin molded parts would not occur. In other respect, since the overlap gates remain only on the back faces of resin molded parts, the resin molded parts remained on the back faces do not cause any troubles in case of operating closely arranged keys.
However, an efficient method for separating the overlap gates and the resin molded parts have not been developed yet, and there is a need of an easy method for separating resin molded parts from the resin molded body in a short time.